Condensation washer-dryers are characterized by a process airflow delivered in a closed circuit system. The process air, heated to a predetermined temperature, is blown in through the back of the motor-driven washer drum, where the items to be dried are revolved and treated with the heated process air. The washer drum is filled and emptied with items to be dried via a front loading opening that can be closed by a door hinged to the front wall. The process air enriched by dampness from the items to be dried is passed through a process air duct leading downwards to the condenser, where the heat from the process air is extracted by cool air drawn in from outside and conducted through a second air guidance system, so that the dampness taken from the items to be dried is condensed and finally discharged.
The condenser is a single component housed in a bottom assembly. Mountings for the drive motor, the fan for the cooling and process air, a condensate drip tray and condensate pump, as well as devices for delivering and guiding process air and cooling air are integrated into the bottom assembly.
The cooled and dehumidified process air is returned to the inside of the drum via a heating device. The delivery of the cooling and process air is by means of fans that are usually coupled with the drive motor of the washer drum.
A condensation washer dryer of this kind, which is typical in its design, is described in DE 102 02 442 A1. The process air duct section assigned to the process air inlet and aligned toward the rear wall of the device has a vertical connecting surface to the heating duct. Additional sealant is provided to adequately seal the process airflow at the connecting surface.
The bottom assembly and the mountings within it for the condenser and the housings for the cooling and process air fans cannot be manufactured as a single piece using injection molding. This assembly has to be manufactured in several single components and joined together to form a unit. In order to achieve adequate sealing, additional sealant is provided at these joints, particularly on the ducts provided to guide the process air.
With known washer-dryers, the heating duct is permanently connected to the rear wall of the device and is mounted on the base assembly complete with the rear wall of the device. The connection is secured by the rear wall being bolted against a frame of the washer dryer. Similar design solutions are also found with other standard washer-dryers.